The invention relates to topically applied cosmetic and pharmaceutical compositions which treat rosacea. In particular, the invention relates to cosmetic and pharmaceutical compositions containing a mixture of components which are substantially non-irritating to the skin when used to treat rosacea.
Rosacea is a common skin condition characterized by symptoms of flushing episodes, erythema, telangiectasia, and the recurring presence of inflammatory papules and pustules on the face usually arranged in a symmetrical distribution across the cheeks and the nose. Fair skinned people are more likely to experience and suffer from rosacea. It is believed that, in general, patients with rosacea have skin that is oily, thin, and has a high microflora count. While many of the effects of rosacea are skin related, rosacea can cause emotional damage because physically it can appear socially unsightly to patently disfiguring. Therefore, any improvement in the treatment of rosacea can have an enormous effect on the lives of those who suffer from this condition.
As a result of flushing and telangiectasia, the facial skin of rosacea sufferers is typically ruddy. The color change observed with rosacea is concentrated in certain areas of the face. It is theorized that the color change associated with rosacea is a result of the dilation of nonmuscular endothelial capillaries and venules. Wilkin, J. K., M.D., et al., xe2x80x9cInfrared Photographic Studies of Rosaceaxe2x80x9d, Arch Dermatol, vol. 116, pp. 676-678 (1980). Provocative factors which trigger the onset of symptoms are well known. These factors include vasodilating stimuli, alcoholic beverages, exposure to heat and sunlight, and Demodex folliculorum. 
Unlike its symptoms and triggers which are well known, the pathology of rosacea remains elusive. One theory is that rosacea is clinically similar to acne vulgaris, and is frequently, therefore, referred to as acne rosacea. Like acne, rosacea exhibits characteristics of sebaceous gland hyperplasi in rhinophyma. However, studies have been conducted to disprove this theory. For example, the skin surface lipid composition of patients with rosacea has shown that the skin surface lipid composition is normal in rosacea and there is no indication of a decrease in free fatty acids when the skin is subjected to a tetracycline treatment regimen. Therefore, it is concluded that changes in free fatty acid levels cannot be implicated in the pathogenesis of rosacea. It is further concluded that rosacea is not primarily a disorder of the pilosebaceous apparatus, Pye, R. J., et al., xe2x80x9cSkin Surface Lipid Composition in Rosaceaxe2x80x9d, British Journal of Dermatology, vol. 94, pp. 161-164 (1976), and thus, it is believed that the processes of acne and rosacea are separate and distinct.
Flushing and the regulatory mechanism of the blood vessels are of importance in the pathogenesis of rosacea. The stages associated with flushing progress from episodes of flushing to persistent telangiectases. Telangiectasia, the dilation of capillaries and small blood vessels, has been studied using infrared photography and results have indicated, consistent with a previously developed theory, that the color change in rosacea is due to the dilation of the nonmuscular endothelial capillaries and venules.
Treatment for rosacea can be orally or topically applied antibiotics, such as tetracycline, clindamycin, erythromycin, as well as vitamin A, salicylic acid, zinc oxide, antifungal agents, or steroids. Another known treatment for rosacea is metronidazole (an antiprotozoal and antibacterial agent) and permethrin (a pyrethroid), alone or with oral 13-cis-retinoic acid (isotretinoin). Signore, R. J., xe2x80x9cA Pilot Study of 5 Percent Permethrin Cream Versus 0.75 Percent Metronidazole Gel in Acne Rosaceaxe2x80x9d, CUTIS, vol. 56, pp. 177-179 (1995). Metronidazole, however, has been reported as ineffective against skin redness, telangiectases and flushing.
Drugs for inhibiting flushing include, for example, methysergide, indomethacin, clonidine, aspirin, promethazine, propranolol, diazepam, and cimetidine. Guarrera, M., et al., xe2x80x9cFlushing in Rosacea: A Possible Mechanismxe2x80x9d, Arch Dermatol Res, vol. 272, pp. 311-316 (1982). In addition, U.S. Pat. No. 5,952,372 discloses a method of treating rosacea with oral or topical use of ivermectin, and U.S. Pat. No. 5,932,215 discloses the use of Calcitonin Gene Related Peptide (CGRP), a substance P antagonist, in compositions to treat skin redness in discrete erythema and rosacea. However, the treatment of the present invention is an improvement over these prior art treatments because known treatments for flushing either do not address other aspects of rosacea such as papules and pustules or are irritating to the sensitive skin of the rosacea sufferer.
It is frequent to find that the skin suffering from rosacea is hypersensitive, and therefore, the treatment for rosacea is or feels particularly irritating to the skin. In fact, most patients with rosacea complain of sensitive skin that stings, burns, and itches after application of treatment compositions, cosmetics, fragrances, or sunscreens because their facial skin is unusually vulnerable to chemical and physical stimuli. Plewig, G. and Kligman, A. M., xe2x80x9cAcne and Rosaceaxe2x80x9d, p. 435 (2d ed. 1993) (hereinafter xe2x80x9cAcne and Rosaceaxe2x80x9d). Soaps, alcoholic cleansers, tinctures and astringents, abrasives and peeling agents are all potential irritants and should be avoided. Therefore, reducing irritation associated with compositions designed to treat rosacea is a special problem. Even more difficult to treat, is the irritation experienced when treating the skin for rosacea complexed with acne vulgaris. Typically products are formulated to be free of irritating ingredients such as actives, surfactants emulsifiers, and fragrances. When this approach is taken, there can be a compromise in the efficacy of the ingredients with respect to their desired activity. It has now been surprisingly discovered, as the foregoing discussion shows, that effective ingredients for treating rosacea, which typically would expect to be or feel irritating to the sensitive skin of rosacea, can be used with not only substantially no irritation, but with a pleasant feel that glides elegantly on the skin.
The present invention relates to cosmetic and pharmaceutical compositions for topical application to skin treated with a retinoid for a condition of rosacea comprising, a phytosphingosine, an antioxidant component comprising at least green tea, an anti-bacterial component comprising at least hinokitiol and a salicylate, and an anti-irritating component comprising at least a polysaccharide and gorgonian extract. The compositions of the present invention are capable of treating the symptoms of rosacea, especially the symptoms related to telangiectasia, such as flushing, while also being substantially non-irritating. The treatment of rosacea is enhanced, and the potential irritation felt on the skin using the retinoid for rosacea treatment is minimized by a combination of the phytosphingosine, the antioxidant component comprising at least green tea, an anti-bacterial component comprising at least hinokitiol and the salicylate, and an anti-irritant component comprising at least a polysaccharide, a gorgonian extract component.
Other features of the present invention are the methods associated with the topical application of the substantially non-irritating rosacea treatment of the present invention. In particular, the present invention includes the method of decreasing the irritation of skin associated with rosacea treatment regimen of topically applied retinoid, the method of treating telangiectasia with phytosphingosine, and therefore, it also includes the method of reducing redness associated with the appearance of rosacea. The present invention is particularly beneficial when used in conjunction with rosacea treatments of topically applied retinoids.